package algorithm.kmp;

/**
 * 暴力匹配算法实现, 逐个比较，一位一位比较
 */
public class ViolenceMatch {

    public static void main(String[] args) {
        //测试暴力匹配算法
        String str1 = "ABABABCDEFF";
        String str2 = "BCD";
        int index = violenceMatch(str1, str2);
        System.out.println("index=" + index);
    }

    public static int violenceMatch(String str1, String str2) {
        char[] s1 = str1.toCharArray();
        char[] s2 = str2.toCharArray();

        int s1Len = s1.length;
        int s2Len = s2.length;
        // i索引指向s1
        int i = 0;
        // j索引指向s2
        int j = 0;
        while (i < s1Len && j < s2Len) {
            // 保证匹配时，不越界
            if (s1[i] == s2[j]) {
                //匹配ok
                i++;
                j++;
            } else {
                //没有匹配成功
                i = i - j + 1;
                j = 0;
            }
        }

        //判断是否匹配成功
        if (j == s2Len) {
            return i - j;
        } else {
            return -1;
        }
    }

}
